Many computer systems have their data backed up on a regular basis. It is very common for enterprise systems to backup their electronic data weekly, daily, or sometimes even hourly. Data libraries often employ backup systems for storing large amounts of electronic data.
One type of media which has been used for backing up electronic data is a magnetic tape drive system. A magnetic tape drive system typically comprises a cartridge or cassette containing a magnetic tape wound around two reels. A cassette interface unit connected to a computer system is designed to read and write to the magnetic tape inside an inserted cassette. An advantage of using a tape drive is that vast amounts of data can be stored at a relatively inexpensive cost. Tape drives are also common in the consumer market as many people wish to backup their electronic data in case of a system failure.
However, because magnetic tape systems involve a lot of moving mechanical part, they use more power and are more prone to environmental contamination or mechanical failure. Another disadvantage of a tape drive is that memory access is sequential, as opposed to most memory devices which offer random access. Due to these characteristics, tape drives are best suited for backup and archiving processes.
Another form of memory media which is becoming more common is solid state, for example, Flash memory. Solid state technology has allowed for smaller memory modules with no moving mechanical parts and fast random read/write access. Solid state drives come in many small forms, such as Secure Digital (SD) cards which fit into small consumer electronic devices such as cameras and cell-phones and Universal Serial Bus (USB) drives.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.